Optimize suppression checks: load once per cycle, add error logging

db.py:
- Add check_suppressed(suppressions, ...) for in-memory suppression lookups
  against pre-loaded list (eliminates N*M DB queries per monitoring cycle)
- get_baseline(): log error instead of silently swallowing JSON parse failure

monitor.py:
- Load active suppressions once per cycle at the top of the alert loop
- Pass suppressions list to _process_interfaces, _process_unifi, _process_ping_hosts
- Replace all db.is_suppressed() calls with db.check_suppressed(suppressions, ...)
- Reduces DB queries from 100-600+ per cycle down to 1

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

db.py

@@ -81,7 +81,7 @@ def get_baseline() -> dict:
         try:
             return json.loads(raw)
         except Exception:
-            pass
+            logger.error('Failed to parse interface_baseline JSON; resetting baseline')
     return {}
 
 
@@ -269,6 +269,19 @@ def deactivate_suppression(sup_id: int) -> None:
             )
 
 
+def check_suppressed(suppressions: list, target_type: str, target_name: str, target_detail: str = '') -> bool:
+    """Check suppression against a pre-loaded list (avoids per-call DB queries)."""
+    for s in suppressions:
+        if s['target_type'] == 'all':
+            return True
+        if s['target_type'] == target_type and s['target_name'] == target_name:
+            if not (s.get('target_detail') or ''):
+                return True
+            if target_detail and s.get('target_detail') == target_detail:
+                return True
+    return False
+
+
 def is_suppressed(target_type: str, target_name: str, target_detail: str = '') -> bool:
     with get_conn() as conn:
         with conn.cursor() as cur: